Automotive Technology/Suspension and Steering
This page is written for those taking the ASE A4 test
- Always mark the placement of any part before removal
Steering
editAlways disable the Air Bag system before any change to the steering column.
Steering Columns should be locked into place to preserve timing and prevent overextending the clock-spring.
Replace Bushings when they no longer hold the part in position. Replace Bearings when they have any visible play, or have a turning torque outside of specification.
Adjustments can affect front wheel toe
Diagnosis
editBump steer can be caused by
- Loose idler arm
- Loose rack mountings
- Loose or damaged mounting
Steering wheel free play can be caused by
- Worn couplings
- worn u joint
- Loose mounting
Steering problems are sometimes subframe alignment problems
Manual Steering Gears
editAlso known as worm gears
Noises, binding, looseness, hard steering point to bearing and lubrication problems.
Rack and Pinion Steering Gear
editOther parts
editAir bag Steering wheel Clock spring
Worm gear Idler arm Rack and pinion
Tie rods
Power Steering Units
editPower steering uses hydraulic pressure to apply force to the worm gear or rack
Diagnosis
editWeeping, or a slight fluid leak requires repair or replacement
- inspect power steering fluid
- Remove and replace power steering pump belt, tensioner, pulley
- diagnose power steering pump problems
- Remove and replace power steering pump
- power steering pressure test
- Remove and replace power steering hydraulics
- Steering gear worm bearing preload and sector lash
- Remove and replace steering gear seals and gaskets
- Remove and replace rack and pinion unit
- Remove and replace rack and pinion steering gear bellows/boots.
- flush, fill, bleed power steering hydraulics
- Diagnose, Remove and replace variable-assist steering systems
- Rack and Pinion Steering
- can provide assistance by applying pressure to one side
Steering Linkage
edit- Inspect and adjust steering linkage geometry
Pitman arm
editPitman arm is only bent in collisions, and wears on other parts. These are pressed on, and are difficult to separate from the splines.
Center link
editIf bent, will affect front wheel toe
Idler arm
edit- Remove and Replace tie rods
- Remove and Replace steering linkage damper
Remove and Replace
Suspension
edit
Front Suspension
editRear Suspension
editAlignment
editFrame
editSprings
editYou should understand spring frequency, even if you never measure the frequency of the spring. Most spring are made of a chrome-vanadium alloy. Very tough stuff.
- Constant-velocity joint
- Usable in torque transfer
Suspension
editASE Task List
editGlossary
edit- Aspect ratio
- Bead
- The lip of the tire that seals the rim flange
- Belt
- Material under the tread
- Center section AKA Spider
- Center of a steel wheel
- Conicity
- DOT tire code
- E-metric tire
- High flotation tire
- Inner liner
- Load index
- Lug nuts
- Major splice
- Offset
- Ply steer
- Rim width
- Run-flat
- Sidewall
- Speed rating
- TPC
- Unsprung Weight
- Weight below the spring in a vehicle
- Uniform Tire Quality Grading System (UTQG)
- Tires sold in the USA are rated in Tread wear, Traction, and Temperature Resistance as per NHTSA.
- Wear bars
- raised features located at the bottom of the tread grooves that indicate the tire has reached its wear limit